From Sahih Bukhari (Hadith 857):
Narrated Sulaiman Ash-Shaibani:I heard Ash-Shu`bi saying, "A person who was accompanying the Prophet (ﷺ) passed by a grave that was separated from the other graves told me that the Prophet (ﷺ) once led the people in the (funeral) prayer and the people had aligned behind him. I said, "O Aba `Amr! Who told you about it?" He said, "Ibn `Abbas
Reference: Bukhari 857